Transmitter, receiver, and amplification system



June 9, 1942. H, KARL l'2,285585 TRANSMITTER, RECEIVER, ANDAMPLIFICATION SYSTEM 3 Sheets-Sheet 1 Filed Dec. l2, 1939 June 9, 194.2.H, KARL 2,285,585

TRANSMITTER, RECEIVER, AND AMPLIFICATION'SYSTEM Filed DSC. 12, 1939 3Sheets-Sheet 2 H. KARL June 1:),4 1942.

TRANSMITTER, RECEIVER, AND AMPLIFICTION- SYSTEM Filed Dec. l2, 1939 3Sheets-'Sheet 3 Patented June 9, 1942 l l UNITED STATES PATENT CFFICETRANSMITTER, RECEIVER, AND AMILIFICA- TION SYSTEM 12 Claims.

Part of this invention is also incorporated in the United States PatentNo. 2,193,874 that was granted to me under date of March 19, 1940, andthe application (Serial No. 116,462) of which was led December 18, 1936,and said part representing a diaphragm that is an invention distinctfrom the remainder of said patent application Serial No. 116,462,division was therefore required.

Said diaphragm, being generally made of a core of certain material and acoating thereon that together produce a clearer and more voluminousvoice than all steel membranes, is therefore more adapted to suit thepublic than the latter. Besides the diaphragm there are otherco-operating means as for instance a novel way of transforming the soundvibrations into electrical impulses that are thus sent to any remoteplace that is in electrical connection with said transmitter and thusbeing adapted to receive said impulses and having them transformed intosound vibrations by the receiver disclosed in the present invention.This invention comprises therefore a transmitter of novel constructionand also a receiver of novel construction and both comprising theimproved diaphragm mentioned above.

'I he invention comprises also such handy construction of thetransmitter and of the receiver, that both can be detached separatelyfrom the standard thereof and simply used as ear and mouth pieces,respectively, whereby only a relatively long cord bearing insulatedconductors, keeps the ear and mouth pieces in electrical connection withthe remainder of the telephone and thus permits the person using thetelephone to hold only the relatively light ear piece in one hand andalso, only if desired, the mouth piece, in the other hand.

The invention comprises also means for securing the ear and mouth pieceto the standard in connection with which they can be used also.

The invention comprises also a new means for making or interruptingelectrical connections with the connecting station and the user on theother end without the necessity of hooking or unhooking the receiver orof placing or taking it oli, respectively, from the socket or other partof the telephone.

Furthermore, the invention comprises novel means for placing the ear andmouth piece on a dish-like part for the easy handling at any time ofthese parts whereby said dish-like part is so constructed thatelectrical connections will be interrupted when the receiver willbelifted from it.

45 larged .the receiver The invention comprises further, new systems ofamplifying the electric impulses set up in the connections of thetelephone and transforming these impulses into sound vibrations.

rIhe invention comprises diaphragms of the re- 15 ceivers, the latter ofwhich are adapted to amplify the sound which is transformed from saidelectrical impulses which are then amplified.

The invention comprises also a system of amplification in which thevoice will be amplied when request therefor is made and such amplicationmay be had only for one of the two parties or for both.

The invention comprises also systems in which telephone amplificationwill be had, whereby one system will be adaptable for near connectionsand another for longer distances.

The invention comprises also suitable connecting places, other thantelephone booths for making connection with the connecting station bymeans of the detached (personal) ear and mouth piece, and thus becomingconnected by telephone with the demanded party.

The invention comprises also suitable boxes or covers for the contactsat said connecting places that are or are not confined in telephonebooths.

Other novel features will appear in the course of the specification.

The invention is illustrated by the accompanying drawings of which:

40 Figure 1 shows the diaphragm of the receiver in front view;

Figure 2 shows the diaphragm of the `receiver in sectional side View;

Figure 3 shows in a sectional view, and enhaving the diaphragm ofFigures 1 and 2;

Figure 4 is a diagrammatic representation of the connection station (orthe central station); Figure 5 is one of the modes of keeping the earand mouth pieec, that is, the receiver and the transmitter, handy on adish-like part;

Figure 6 is a sectional representation of the receiver having a coneshaped diaphragm;

Figure 7 shows the diaphragm of the transmitter. in front view;

showing also diagrammatically electrical connecl tions and a standard towhich the transmitter can be affixed and detached at will; showing alsoa circuit connector for establishing electric circuit connection withthe connecting station;

Figure 11 shows in sectional elevation another l5 type of transmitterwhose primary and secondary windings of the transformer are separatedfrom the hull of the transmitter proper although being in electricalconnection therewith and the transmitter being of a type that bears acontainer of 20 gaseous or of liquid or of a semi-liquid matter fortransforming the sound vibrations into electrical impulses and havingalso a circuit connector for the electrical circuit connection with theconnecting station, whereby this connector is 7.25

different from the one shown in Figure Figure 12 shows another purelymechanical intermediary means for transforming the sound Vibrations ofthe diaphragm into electrical impulses;

Figure 13 shows in section the mechanism of the connector shown also inFigure 11;

Figure 14 shows the special contact cover and coin box;

Figure 15 shows the telephone connections with `35 ampliers;

Figure 16 shows simplified telehpone connections with amplifiers`Referring to the diaphragm of Figures 1 and 2 there is a frame I onwhich is stretched a sheetj- "4() of paper 2, of suitable quality andthickness or a piece of slik or of rayon or one of other cloth mayserve. A very thin piece of wood, of such character, that like r, isvery adapted to create* sound vibrations, is also adaptable. or cloth ofsilk or rayon or said thin piece of wood is to be properly lacquered orvarnished and especially with the kind of lacquer that dries very hard,such as the lacquer used for lacquer-f If cloth is taken, such as, silkor ing Violins. rayon or others, it might be necessary to make thediaphragm of cone shape in order to stretch the cloth sufficiently. Anexample of a cone shaped diaphragm of a receiver is shown in` Figure 6which will be described subsequently. 5

If paper is to be used for making the diaphragm it should be made wetwith water and mounted on the frame I in moist condition. It will thenbe properly stretched and allo-wed to dry thor-` oughly. In thecompletely dried condition th paper is then suiiiciently stretched andcan be lacquered. This procedure applies also to the diaphragm shown inFigures '1 and 8.

Referring again to the diaphragm 2 of FiguresI 1 and 2 there must beiron filings 3 strewn on the 65 still wet lacquer and especially at thepart of the paper that will be nearest to the poles of the electromagnetthat is then included in the receiver, as can be seen from Figure 3. Theiron filings 3 are then only situated around the center To of thediaphragm and only on the side that faces the poles of the electromagnetwhen it deals with a receiver, which is contrary to a known example of areceiver diaphragm which is entirely made of hard rubber or shellac orCelluloid or Choroshows in sectional elevation the 5 This paper 5lithion or other materials in which iron in foraininated or comminutedform may be embedded, which is then contained in all parts of the wholediaphragm. By embedding the iron filings only in the lacquer that coatsthe side of the core of the paper etc. and especially only the area thatfaces the poles of the electromagnet, vibration of the diaphragm will beobtained at the slightest electromagnetic impulse in the electromagnet,as will be explained further subsequently, and the vibrations will bethe more pronounced when the far greater part of the diaphragm is leftfree from iron particles that tend to make it heavy. In the latter gureis also shown that the electro-magnet comprises two cores or Shanks 4, 5which are partly enveloped by the windings 6, 1, respectively The shanks4, 5 are connected to the Shanks 8, 9 of the permanent magnet l. The endII, I2 of the shanks 4, 5, near the diaphragm, should be about l, 11/2or 2 of a thousandth of an inch distanced from the diaphragm 2.Connected to the winding 6 is the wire I3 and connected to the winding 1is the wire I4, and all are in the same circuit. The latter may begrounded at I5, while the wire I3, forming also part of the circuit, isextended to the connecting station, shown in Figure 4, where it forms acontact I5, in which can be inserted the contact I1. This will takeplace when the operator received a call to connect with the contact I6which might have a special other number. The operator at the connectingstation thus connects the circuit, which when closed, rings the bell I8.

The parts of the receiver that must be kept together, as, the frame I,the diaphragm 2, the electro-magnet 4, 5, the permanent magnet I and thewindings 6, 1 are held together by the frame I9 of insulating materialwhich has the special ear piece 20. The conductors I3, I4 are continuedin a cord 2|, of known make, and are surrounded by insulating material22.

For protecting the diaphragm 2 a wire screen 23 is placed a little infront of the diaphragm and held in the walls of the ear piece 20. A ring24 may conceal the end of the narrow hose of the cord 2 I.

The receiver of Figure 3 may be placed on a dish-like part 25 (seeFigure 5) which has its bottom formed as two contacts 26 and 21, ofwhich the one indicated by 26 will be separated from the contact 21 whenthe receiver will be lifted, as when the person, hearing the sounding ofthe bell I8, is to listen to the message coming over the telephone andthus places the receiver to the ear. The electric circuit causing theringing of the bell I8 will be interrupted thereby and the ringing ofthat bell thus stops. rihe fiat contact 25 will be lifted and thusdisconnected from the flat contact 21 by the spring 28.

' For announcing that somebody is listening and for making theconversation with the party at the other end of the wire the person thatlifted up the receiver first, must then use also the transmitter ormouth piece 29 which may be Vplaced at some other part of the dish-likepart 25, as

shown in Figure 5. The details of the transmitter will be describedsubsequently.

Referring to the cone shaped diaphragm 30, shown in Figure 6, itconsists preferably of cloth such as silk or rayon although cotton maybe .used also, The piece of cloth will be stretched on the frame 3|,whereby the center point wil be held forward by a forward protrudingpart 3i diaphragm 36, being also the diaphragm of aA receiver, must alsohave the iron lings embedded in the lacquer that covers the surfaces ofthe cloth or other suitable material.

The cores 34, 35 of the electro-magnet 36 thus must have the ends soinclined, est t the diaphragm, that they Will have the same direction asthe cone shaped wall of the diaphragm, in order to be very close to theinner surface of it, but without touching it. 31 indicates the permanentmagnet and 38 the part of the frame or hull that will be held againstthe ear. There might be a cone shaped protection screen 39 employed. Theother parts of the receiver of Figure 6 are otherwise like those shownalso in Figures 3, 4 and 5.

From the description of the receivers it is shown, that the electricimpulses set up in the windings 6, 1 of Figure 3 or the windings 46, lllof Figure 6, energize the cores 4, 5, 34, 35, respectively. These cores,being thus made magnetic in the degree which is commensurate with thedegree of the electric impulses, attract alsc` the iron filings that areembedded in the lacquer of the diaphragms, and since these iron lingscannot separate themselves from the lacquer and consequently from thediaphragms, the latter must therefore make the movements or vibrationswhich are caused by the alternate attraction and then release of theiron filings that are embedded in the then hardened lacquer. Thestiffened diaphragms, being thus forced to vibrate, produce therebysound waves that conform with the electric impulses set up in thewindings and cores of the receiver.

In order to synchronize the Vibrations of the diaphragm of the receiverwith those of the transmitter it is therefore advantageous to make thediaphragm of the transmitter of the same material that is taken formaking the receiver, whereby no iron filings will be embedded in thelacquer. Using for the transmitter the same material of which consistthe receiver, is however, not an absolute necessity, since thetransmitter diaphragm might consist of one of said other materialsmentioned before and even the al1-steel membrane might be retained undercertain circumstances.

The reason why the materials mentioned, that are non-metallic, arepreferable over all metallic diaphragms is, because these materialsdiscounting the frame l, 3|, respectively, and in cooperation with thehardened lacquer being lighter and more sensitive than metallicdiaphragms, are adapted to make more pronounced vibrations than thesteel membranes and consequently will react upon the slightest impulse,either the sound or the electric impulse. Since then the strong andmedium impulses are also proportionally increased there is a greaterperceptibility of the sound created by the receiver than it is the casewith the all steel diaphragm. This permits again that other parts in thereceiver, as well as in the transmitter can be made smaller in size thanwith the transmitters and receivers, the diaphragms of which are in theform of steel membranes, without impairing thereby the vibrations of thediaphragms.

Referring to the transmitters of which two complete examples are shown,namely, one in Figure 10, which will be described rst, and-one which arenearin Figure 11, one of the purposes of the invention is to make themouth piece 42 detachable from the standard 43.y This permits to holdthe relatively small mouthpiece (the transmitter) in one hand and therelatively small receiver (the ear piece) in the other. Many personslike to walk back and forth while talking and do not like to haverelatively voluminous or heavy instruments in their hands. Thetelephoning, while being in bed or in any other situation, is thus madeeasy and consequently more agreeable. A business man may carry the mouthpiece and the ear piece in his pockets while being in the oflice or inany other place, and may detach them from the contacts 45 that haveguide channels'46, 41 into which can be inserted the contact extensions48, 49 (the insert) that form part of an attachment 56 to which areproperly connected the wires 5|, 52 in the cord 53. The Wires 5|, 52 areinsulated froml each other, as are also the metallic walls of the guidechannel 46 from those of the guide channel 41. The contact extensions48, 49 are also insulated from each other and the former is electricallyconnected with the wire 5| while the other is connected to the wire 52.To the metallic wall of the guide channel 46 is electrically connectedthe wire 54 while to the metalic walls of the guide channel 41 iselectrically connected the Wire 55, which is grounded at 56. Wire 54 isextended to the connecting station that might be the central station.Wire 54 must be in connection with the contact I1.

Another pair of guide channels 51, 56 are provided for to permit theinsertion of the Contact extensions 59, 66 (the insert) of the receiver(see also Figure 3). The metallic walls of the guide channel 51 are inelectrical connection with the wire 54, while the metallic walls of theguide channel 58 are in electrical connection with the wire 55.

If the telephone company would provide guide channels as explained inconnection with Figure 10, with every telephone booth and also at manyother convenient places, it would facilitate those persons that carrywith them their personal receiver and transmitter, to converse bytelephone from any of the numerous places by using their own set oftransmitter and receiver (the mouth and ear piece). A regular telephonebooth might be only miles away.

This innovation is not only made to suit fastidious people that do notlike to handle receiversand transmitters that have been handled bynumerous other enormously simplify the system and reduce enormously thecost of installation of the so simplied apparatus. It would then suitgreatly the user of the telephone that may carry his own mouth and earpiece, and would suit greatly the company for the economic and simpleway of installation. Y

Referring more particularly to the scheme shown in Figure 11 the mouthpiece (the transmitter)l will be detached from the primary and secondarywinding 6|, 62, respectively, of the transformer 63. The transmitter,thus being reduced in weight, can be made so light and small that it canbe carried in the vest pocket. It will then be necessary to install thetransformer 63 in some secure place and connectit by the wires 64, 65 tothe metallic walls of the guide channels 61. The battery 68 must then be'ineluded-in this part circuit as well -asA the primary Winding 6|. Itwill be comformable to indicate people, but the scheme wouldl by sign orother information, if the guide channels their walls, respectively, arein electrical connection with a transformer. There might be thereforetwo kinds installed of which one is and the other is not in connectionwith a transformer.

'Ihe circumstance that the diaphragm can be relatively small permitstherefore also to make the transmitter comparatively small. Thetransmitter of Figure may be used at such numerous places by workmen ofthe telephone company or other agents, in which no transformers are tobe installed, while the transmitter of Figure 11 will be used only byprivate persons, at such places, where the transformers are also inelectric connection with the walls of the guide channels.

Other arrangements in the use are obviously possible and alsomechanically there are deviations possible, as for instance, the guidechannels for the inserts may be arranged at the ends of the wires thatare permanently associated with the transmitter (the mouth piece) whilethen the wires being permanently in electrical connection with theprimary winding of the transformer must then be connected to the insert.

In connection with the receiver the insert may also replace the partwith the guide channels while the latter will then be part of thedetachable portion of the receiver.

In order that the telephone company may be duly recompensed for the useof the telephone connections and the service of connecting, there are ingeneral two ways for receiving its dues. One of these ways consists byincluding a general fee for a large number of calls when a personacquires a set consisting of a receiver and a transmitter for personaluse only. In this case the person that acquires the receiver andtransmitter will also be handed a key 68 by means of which the cover 69can be unlocked and turned in such position that it permits theinsertion of the insert. A similar cover should also be in connectionwith the transmitter guide channels. The cover 69, however, should bebig enough to cover all four guide channels, namely, those indicated by46, 41 and 51, 58.

Since the scheme in connection with the transmitter of Figure 11 issimilar to that shown in Figure l0 the same applies also to the guidechannels that will be used for connecting the transmitter of Figure 11and a cover will serve for protecting the otherwise exposed contacts,whereby the person, having the key, can thus open the cover and insertthe inserts of his mouth piece (the transmitter) and ear piece (thereceiver) The other mode of getting its dues is, that the telephonecompany provides a nickel drop near every lock of the cover B9 and toconstruct the lock so, that part of it prepares the lock bolt for beingpushed to open position which is then effected by the key which thecaller carries with him and which should be suitably attached to thetransmitter or to the receiver.

A convenient structure of such lock is illustrated in Figure 14. Thecover 69 is shown partly broken away to show the other mechanisms thatco-operate with the lock. The lock bolt 1|) is thus shown in lockingposition, whereby a spring sustained relatively thin bar 1| will bemoved between the wall 12 and the end wall 13 of the bolt 10. The latterthus cannot move backward, even if the key is inserted and it is triedto turn it. Only after the insertion of a coin, say a nickel, the thinbar 1|, that might iii) be pivoted, will be pushed down and out of theway of the lock bolt 10. The additional weight of the nickel forces therelatively weak spring 15 down, bringing thus also the thin bar' 1| downand in engagement with two spring contacts 16, 11 that usually areseparated from each other. These contacts 16, 11 form part of anelectric circuit by means of which, and in co-operation with a soundingor visually perceptible means, will be announced that a nickel has beendropped in that certain box. The operator in the connecting station maythus make a note etc. and then disconnect temporarily the bell or whatever means are employed for announcing the insertion of the nickel andwill then listen to the caller and make connection with the demandednumber. At this instant the caller might ask for amplification if heshould be hard of hearing or if he simply likes it better, or if severalpersons are eager to listen at the same time. The details in connectionwith the amplification will be pointed out subsequently.

The spring contacts 16, 11 are so formed that they hold the thin bar 1|and thus allow the nickel 18 to drop through another slit to fall into aspecial box, especially provided for the coins. This special box isshown underneath and since similar boxes are well known, is not furtherdescribed; the same will be also provided with adequate locking means asknown. The lock bolt 10 is always urged by the spring 1S to the forwardposition in which it locks the cover 69 when the latter is pressedagainst the casing Bil. While thus locking the cover 69, a part 8| inthe box will separate the two spring contacts and the thin bar 1 I,being urged upward will then be situated between the wall 12 and therear edge 13 of the lock bolt 10 and will thus prevent the latter to bemoved by a key, or moved otherwise, to open position unless the requiredcoin is inserted. It will be noted, that through the forward urging ofthe lock bolt 16, by the spring 19, no pressure will be exerted upon thethin bar 1| excepting a temporary pressure when somebody tries to movethe lock bolt 1E) to open position with a key without, however,inserting the coin. The thin bar having no obstruction, other than thatof the spring 15, readily moves down, following the weight of thenickel.

Referring to the other details of the transmitters the diaphragm, whichmight also be coneshaped, as shown in Figure 9, does not need to haveiron filings embedded in the lacquer that covers the cloth, or paper, orthin wood piece, but for creating a diaphragm that has the same weightand consequently the same vibrating quality as has the diaphragm 2 or3:1 of the receiver, there may be iron filings strewn in the still wetlacquer that covers the cloth, paper .or wood, or other suitable fibrousmaterial, of the diaphragm. The synchronization will thus be had thatrenders the electric impulses into sound waves that correspond withthose caused by the person that speaks into the transmitter.

The transmitter of Figure 9 that has a cone shaped diaphragm 82 issimilarly constructed as the diaphragm of Figure 6. In addition,however, there are lacquered fibres or bristles or horse hair, that islacquered, or other delicate means B3 of certain stiifness andflexibility, that are secured to the part of `the diaphragm thatvibrates the most vigorously, which is the part between the apex 33 andthe frame 3|, and which means are adapted to translate the vibrations ofthe diaphragm 82 upon the metallic membrane 84, which does not need tobe of steel, but of any other suitable metal, as for instance silver,copper or brass. The ends of these fibres etc. 83, that touch themetallic membrane, should advantageously be provided with an insulatingmaterial, so as to prevent electric energy to deteriorate or burn thefibres etc. and also the diaphragm, because the metallic membrane formsa connection of an electric circuit. Behind the metallic membrane 84there is metal Wool 85 placed which should touch the metallic membraneand also the conducting plate or part 86. Instead of the metal woolthere might be granules of carbon or graphite or charcoal employedalthough the metal wool, preferably of a good conductor, is preferableon account of its better conductivity and flexibility. To the metallicmembrane 84 is connected the wire 87 which leads to one of the ends ofthe primary winding of the transformer, which is not shown, but sincethe mouth piece shown in Figure 9 is supposed to be of the character ofthecmouth piece shown in Figure 11, which is detachable from the partthat embraces the transformer, reference is therefore had to thatparticular arrangement, shown in Figure 11, which has been describedpreviously. Referring again to Figure 9 the wire 88 that is connected tothe plate 88 leads to the battery which in Figure 11 is indicated by 89.The wire indicated by 84 in Figure 11 leads then to the other end of theprimary winding ,to which it is connected.

Referring to the Figure 10 the diaphragm 99, shown also in Figures 7 and8, is flatly mounted on the frame 9|, and the latter is insertable inthe hull 42. The diaphragm 90 may have also the iron filings 3 as it iswith the diaphragm of the receiver, but only for synchronizing purposes,as has been explained previously.

At the interior side of the diaphragm 99, and centrally located, thereis a part 92 secured that must be very light and which could consist ofthe marrow of some plants or of cork and the free end should be coveredwith insulating material. A Very ne leaf spring 93 is secured with itsone end at 94, Where it is insulated from other parts, but a conductor95 is electrically connected thereto. The free end partrslightly touchesthe insulating material on the part 92 and the free end part of anotherfine leaf spring 96 touches also slightly the leaf spring 93. Leafspring 98 is'secured with its other end to the plate or wall 9'! whichis in electrical connection with the primary winding 98. The latter hasalso at its other end a conductor 99 which leads to the right side ofthe battery |99. To the left side of that battery is connected the wire95. To the secondary winding |9| is connected the wire 52, while thewire 5| is not directly connected to the other end of that winding.There is a push button |02 of any convenient character with which anelectrical connection and disconnection between said other end of thesecondary winding |9| and the wire 5| can be made. This switching device|02 might chiefly serve when the insert of the transmitter is insertedin the guide channels at home, but no conversation is intended. The pushbutton thus will remain in circuit disconnecting po-I sition. Even withconnecting contacts 45 (guide channels) at other places than the home,the push button will be handy for interrupting communication until theright moment is at hand. In order to restore the push button |02 tononcontacting position, in which it interrupts the electrical connectionbetween the wire 5| andthe secondary winding ,|0|, after it had beenpushed in to contacting position, there is another push button |03arranged at the opposite side of the hull and a partly curved rod |94 issecured to it and also to the push button |82. If then the push button|02 will be pushed in, the push button |03 will then be pushed out, andthe push button |02 is then in contacting position. By pushing then thepush button |03 in again the push button |02 will thus be pushed out bythe rod |04 and will make said disconnection between the wire 5| and thesecondary winding |0| Looking now at Figure 4 it will be seen that thebulby |95 will light up when the circuit will be closed that comprisesthe battery |00, because the wire 54 also shown in Figure 10 is inelectrical connection with the secondary winding |0| whose other end isgrounded at 58. The operator at the connecting station may then connectafter any known kind of announcement including the voice of the caller,the contact (switch plug) I1 with the contact I6 and thus establish anelectric connection with the bell I8 and with the receiver of Figure 3or Figure 5 or both.

In Figure 11 the main purpose of the construction consists in reducingstill more the weight of the transmitter, so that the latter may becarried easily in the pocket of any person .or in the hand bag of alady, including also the receiver of Figure 3 which is also the oneshown in Figure 5, or it may be the receiver shown in Figure 6.

The transmitter of Figure 1l vdistinguishes itself greatly from thetransmitter of Figure 10. The diaphragm |01 is similar to the diaphragmand is also similarly mounted on the frame |08. At the center of theinterior side of the diaphragm |01 there is a light part |09 secured, inwhich is inserted bristle H0. The right side end of the wire or bristle||0 abuts against a steel membrane or one o-f any other suitable metal,such as silver, copper etc. This membrane closes up a vessel ||2 ofglass or porcelain ,or of any other suitable insulating material thatshould have an opening |3, that can be tightly closed by a stopper orthe like means lill.

conductor ||5 that is secured to a plate H8, which may be of copper .orof any other suitable metal.y The conductor H5 is extended into the cord||1 and is insulated therefrom. Likewise is also a conductor H8 extendedinto the cord ||1 and insulated from both the latter and the conductorH5. Conductor I8 is secured to the metal membrane at a part that isnearest to the outer edge thereof, and the other end of that conductorforms the insert extension ||9 that is insulated from the insertextension |20. The latter is the end formation of the conductor ||5.

Into the vessel ||2 will be introduced the gas or vapor that is known tobe a good electricity conductor and which is also adapted to correctlytransform the vibrations of the membrane into electrical impulses whenan electric-current is passed through it. It is therefore important thatsaid gas or vapor has the correct density and that only then the closingmeans` I4 should close up the vessel I |2.

Any gas that does not explode or expand too heavily will be suitable,and in such category may be ranged lighting gas although others may beeven better. Among the vapors, that could a very fine but stiff wire orAtthe center of thev right side wall of the vessel 2 penetrates a.

6 be used, must be ranged first the fumes of mercury.

Instead of fumes or gas there might be liquids o-r semi-liquids filledin the vessel H2, which again might contain suitable ingredients. One ofthese semi-liquid means might consist of paste in soft condition or anysuitable kind of jelly having carbon or charcoal dust or powderedgraphite, iron, silver or copper or brass mixed therein in certainproportion.

Ifl the insert extensions IIS, |20 are inserted into the guide channelsof the stationary connecting part 51` the electric circuit will beclosed that comprises the following conductors: the battery 68, the wire64, the primary winding 6I of the transformer 63 the wire E5, the wallsof the guide channel in which is inserted the insert |20, the wire II5,the plate I I6, the gas or fumes or liquid or jelly etc. in the vessel II2, the membrane I, the wire IIS., the insert extension IIS, the'wallsof the guide channel in which the eX- tension II9 is inserted, the wireI2I that is connected at the left side of battery 68.

The person speaking against the diaphragm |01 brings the same therebyinto vibration and these vibrations are transmitted to the metallicmembrane III by means of the wire or bristle I |0. The gas or fumes orother mentioned matter contained in the vessel II2 takes up thevibrations made by the metallic membrane I I I and since electriccurrent flows at the same time through the metallic membrane II I andthrough the fumes or gas or liquids etc., the Vibrations will thus berendered into electric impulses, which the plate II 6 takes up andimparts to the primary winding 6| through the wires II5, II8, the insertextensions H9, |20 and the contacts in the connecting part 61, thebattery 68 and the wires 64, 65. The secondary winding 62 still moreclarifies the impulses and if the connector |23 is in closed position,conversation can then be had with the connecting station and when theoperator cc-nnects with the number that is demanded, conversation willthen be had with the party whose telephone is thus connected.

The secondary winding 62 is in electrical connection with the connectingstation shown in Figure 4 or Figure 15 or Figure 16 and has similar`connections as has been explained in connection with the Figure 10.

In order to make the mouth piece of Figure 11 as light as possible sothat it can be carried4 in the pocket of its owner, the connector is notincorporated with the mouth piece, but is brought in connection with theconductor |22 and is indicated by |23. For connecting the mouth and earpiece at such places that are remote from the home or olce theconne-ctor will not be needed, since electric connection will beestablished with the connecting station at the moment the inserts areinserted in the guide channels.

The connector |23 which is shown in section in Figure 13 has a pushbutton |24 that is movably arranged in the body |25 of insulatingmaterial, and that push button bears the contact part |26. The latter isso formed at its ends that they (the latter) snap upon the ends of thewire-s |21, |28 when the push button |24 is pushed in. Electricalconnection is thus created between these two wires. The push button |29has a part |30 that is also connected to the push button |24. If thenthe push button |29 is pushed inwards the push button |24 will be pushedoutwards and disconnects its contact part |26 from the wires |21, |28.

Having described the details of some preferable types of the receiversand transmitters it is to mention that the non-metallic diaphragms aregreatly advantageous for the transmission and reception of the amplifiedvoice. This permits again the installation of amplifiers of the radiotype at the connecting stations (see Figures 4, 15 and 16) where theelectric impulses coming over the wire will then be amplified uponrequest. Various forms are thus adaptable. In one form shown in Figure4, the operator at the connecting station disconnects the contact I1from the contact I6, but closes the switches |32 and |33. Through thisaction the wire 54 or |22' will be brought into electrical connectionwith the amplifier B andthe wire I3 will be electrically connected tothe amplier C. If the caller at the transmitter that is connected to thewire 54 or |22 requests that the operator connects the amplifier andtunes it up to the desired volume, the electric impulses set up in thewire I3 and the secondary winding of the transformer, that is inelectrical connection with the wire I3, thus will be amplified in theamplifier C, and in such state the electric impulses will be impresseduponY the wire 54 or |22 and consequently the electromagnet 4, 5 or 34,35 of the receiver'vibrates the diaphragm in .such degree that the voiceproduced thereby is in intensity above the voice that is derived fromelectrical impulses that did not receive amplification. On the otherhand the wire 54 or |22 that is in electrical connection with theamplifier B might also have the electrical impulses amplified if it willbe so requested from the party at the receiving end of the wire. If nosuch request will be made, then the amplifier B will be tuned only tosuch degree in which the electrical impulses originated by thetransmitter in connection with the Wire 54 or |22' and the respectivesecondary winding thereof of the transformer will be transferred withoutamplification upon the wire I3 and the electromagnets 4, 5 or 34, 35 inabout the same degree as they are produced in the wires 54 or |22. Thecircumstance, that the party listening at the receiver at the end ofwire I3 will hear its own Voice amplified, makes it the-n necessary tocover the front side of the ear piece, in any suitable way, whiletransmitting, that is, speaking into the transmitter; or the ear piecemay be simply held away from the ear.

This inconvenience, which is caused by the amplication of the electricimpulses set up in the wires 54 or |22 and transferred through theamplifier B to wire I3 and the receive-r at the other end, can beremedied when a special wire |34 (see Figure 15) will be connected tothe secondary winding of the transformer of the transmitter T, wherebythe wire 54 will be connected to the receiver R. only.

By separating the amplifier D completely from the wire 54 and connectingthe wire |34 to the amplifier D by means of the switch |32 amplificationwill be had in the receiver RI, over the wire I3. If the party at thereceiver R wishes to have also amplification of the words coming overthe wire, the operator, when thus informed, disconnects then the contactl1 from the contact I6 and closes the switch |33'. The Words spoken intothe transmitter TI will be amplified by the amplifier E and in suchamplification will be had at the receiver R. In order that the own wordswill not be heard in the receivers by the person speaking into thetransmitter T or T', the `switches |34', |35 should be opened.

A simplification of the system, shown in Figure 16, is that only onewire leads from the receiver R2 and the transmitter T2 to the connectingstation F and also only the wire |3" from the receiver R3 and thetransmitter T3 to said connecting station F. In order to avoid that theown words will be heard at the receiver by a person speaking into thetransmitter not to say the amplified voice, there is a system of 'verysensitive relays employed that act at the slightest electrical impulsethat energizes the cores of said relays. For simply connecting thetelephones of two parties that wish to have conversation with each otherthe contact (the insert or switch plug) is to be inserted into thecontact |6. The party using the receiver R2 and the transmitter T2,wishing to have the words amplified that come from the connected phonewith the receiver R3 and transmitter T3, order so from the operator atthe connecting station F. The operator pulls then the switch plug |1'outof the contact I6 and closes the switch |31. Electric connection is thusestablished between the receiver R3 and transmitter T3, on the one handand the amplifier G, on the other. It must be remembered that thearmature |43 normally is in its dropped position in which it contactswith the contact |44. The amplified electric impulses are impressed uponthe winding of the relay |39 by the wire |38. 'Ihis relay attractsthereby its armature |40 and the latter becomes thus disengaged from thecontact |4| of the lead |42 that leads to the amplifier H. The ampliedelectric impulses thus cannot ow to the amplier H and are forced toconcentrate -on the receiver R2 and the secondary winding of thetransformer |45 that is grounded at |46. The electromagnet 4, 5 (or 34,35) in the receiver R2 vibrates the diaphragm 3, 30), commensurate withthe degree of the electric impulses, which it receives, and sin-ce theyare then amplied, the voice, created by the vibrations of the diaphragm,is then also commensurately amplied.

. multaneously with the The armature |40, being thereby disconnected yfrom the contact I4|, no sound, that was spoken into the transmitter T3,will be heard amplified at the receiver R3.

The party at the telephone with the receiver R2 and transmitter T2 mustalso be able to communicate (speak) with the party at the phone with thereceiver R3 and transmitter T3; therefore, as soon as the armature |40drops electric connection is established with said party at the right,namely the phone with the receiver R3 and the transmitter T3. Theelectric connections, include the wire |42, the amplifier H, which,however, is tuned only to the degree which will produce a sound at thereceiver R3 that equals that which is obtained when no amplificationwill be had, that is, when the contact |1 is simply connected to thecontact I6. The relatively weak electrical impulse is adapted toenergize sufficiently the core of the relay |49 so that the armatures|43 and |50 will be attracted and an electric connection with thereceiver R3 and the secondary winding 62 of the transformer 63 isestablished, whereby said secondary winding is grounded at |55.

If the party at the telephone of the receiver R3 and transmitter T3wishes to get also amplification and noties the operator at theconnecting station F, the operator simply tunes up the amplier H to thedesired volume. The amplication will be impressed upon the lead |48, thewinding of the relay |49 and since the armatures |43 and |50 areattracted thereby connection with the ampliiier G and conductorsassociated therewith will be severed, but electric connection with thereceiver R3 and the secondary winding 62 and ground |55 (transmitter T3)established. The party at the phone of the latter receiver andtransmitter will thus have amplification in the desired degree withouthaving its own words amplified at the receiver R3 that are spoken intothe transmitter T3.

A still greater simplication consists, in using only one amplifier, asfor instance'the one indicated by G. In this event ;the switch plug(contact) I1 is to be contacted with the wire |52 or directly with theproper contact of the amplifier G. A wire is then to be connected to thewire |38 and to the winding of the relay |49. Amplification, however,will be had at the receiver siown words spoken in the transmitter.

The system illustrated in Figure 15 might vbe advantageous withconnections in which relatively little wire will be needed as, forinstance, when it deals with an installation that is limited to thehome, an estate or to a factory or to some not too far distanced orneighboring buildings only. The system contemplated in Figure 16,however, is more adapted for longer distances and long distance calls,since only one wire is needed to connect the receiver and transmitterwith the connecting station, the central station, respectively. There isat least one great advantage in connection with the ampliiiers that aresituated at the connecting station only, because the necessary care andcorrect handling and better protection of the same is thus assured andnot many amplifiers might be needed.

Referring to the transmitter of Figure 11 there is also a standard |31contemplated that is indicated by dotted lines. Since the structure andshape of the mouth piece differs from that of Figure 10 a method istherefore adaptable in which by means of hooks 38, |39 the mouth piecewill be held in vertical position, which is the position in which thediaphragm is also vertical. A spring |40 will urge the hook |39 againstthe hull 29 and the springy part |4| will pull the hook |38 andconsequently the upper part of the hull 29 against the standard |31,permitting at the same -time the separation of the hook |38 from thehull 29 and the latter from the hook |39 and then of the standard |31.The latter may also have al1 the improvements which are, for instance,known with standards of microphones.

Referringto Figure 12 the scheme employed might nd as well use with thedisclosure of Figure 9 or even with that of Figure 10. It consists ofplacing carbon granules |43' or graphite or charcoal or a mixture ofthese ingredients-in the space, situated between the metal membrane |44'and the metallic wall |45', which is in electrical connection with theprimary winding of the transformer, shown only in Figures 10 and 11. Themembrance |44' will be Vibrated by the diaphragm |46', its attached part|41', respectively, whereupon the granules |43 transform the Vibrationsinto electrical impulses. In connection with some of the receivers,especially those that have cone shaped diaphragms, as, for

instance, shown in Figure 6, the pole ends of the cores of theelectro-magnetl may consist of two or more branches when it deals withcores that must be close to parts of the diaphragm that vibrate the mostviolently. One branch 8 end may thus face the part of the diaphragm thatis half Way between the outer frame and the center point, the apeX ofthe diaphragm, and the other somewhat nearer to the apex, as also shownin Figure 6. The former may, however, suflice in this case.

summarizing the invention, first, the diaphragms of the receivers aswell as of the transmitters are contemplated to be of other materials,chiefly fibrous materials, than of all metal, because the atomicstructure of metals is not so favorable for giving the membranes, madeof metal, the relatively wide range of vibration which is, however,inherent with the materials contemplated in the present invention. Themeans for coating the diaphragms, of which lacquer, or a certain kind ofvarnish is contemplated, protect the diaphragm as it gives also thevibrating quality to it when in dry condition.

Therefore, through the addition of iron filings in the lacquer thatcovers said non-metallic material of the core of the diaphragm of thereceiver and especially the side of the core and only the area thatfaces the poles of the electromagnet, the electromagnetic impulses willbe transformed into sound vibrations.

Further, a system is created in which thanks to the non-metallicdiaphragm, being adapted to increase the sound vibrations and thusincrease the volume of the voice caused by the electrical impulses sentover the wire, the decrease of the size and weight of the ear and mouthpiece is thus permitted.

Furthermore, the forming of the ear and mouthA pieces as detachableparts that can be used as the personal ear and mouth piece and which areadapted to be carried in the pocket or in a hand bag, when not in use,is one of the results.

Furthermore, the ear and mouth piece (the receiver and transmitter),through their wider range of vibrating movement, permit theampliiication of the electric impulses set up and the commensurateamplification of the sound with the receiver, the ear piece.

Furthermore, since amplification should be made only when so ordered,the system comprises therefore such connections and apparatus thatpermit amplification only for the party, asking for it, wherebyamplification will be had in the desired volume for all, that is the twoparties speaking together over the telephone, if so rdered and theconnections are made.

Furthermore, thanks to the proper arrangements of the electricconnections and certain other means of one simplified embodiment, thewords spoken into the transmitter by a person will not be heard inamplified volume in the receiver to which listens that person.

Furthermore, the system comprises also such other electric connectionsin which the words will not be heard at the receiver at which the personlistens that speaks them into the transmitter.

Furthermore, such simplified electric connections are also devisedwhich, however, amplify the words spoken into the receiver if suchampliiication is demanded, whereby the words spoken into bothtransmitters will be heard in amplified volume at both receivers.

Furthermore, the fact that the transmitter and receiver can be detachedand carried on the person that possesses them, permits the installationof contacts with electric connections leading to the connecting station,whereby these contacts do not need to be confined solely in telephonebooths, in which, however, they may be arranged also.

Furthermore, the creation of new means for the transformation of thesound vibrations into electrical impulses favor the clear and voluminoustransmission of the voice and favor also the amplification thereof.

Furthermore, the addition to the diaphragm of the transmitter of ironfilings for synchronization with the diaphragms of the receivers.

Furthermore, the creation of the cone shaped diaphragm and of the fiatdiaphragm.

Furthermore, the creation of a handy dish-like part on which the lightand handy ear and mouth pieces can be placed so as to be ready for theuse at any time.

, Furthermore, the use of liquid and semi-liquid or jelly like means forthe transformation of the sound vibrations into electrical impulses.

Furthermore, the use of metal wool for the transformation of the soundvibrations into electrical impulses.

Furthermore, the arrangement of fine springs for the transformation ofthe sound vibrations into electrical impulses.

Furthermore, the transmission of the vibrations of the non-metallicdiaphragm upon a metallic membrane.

Furthermore, the disconnection of the battery, the primary and thesecondary windings of the transformer from the transmitter, thuspermitting the latter to be very light and adapted to be carried on theperson when not in use, and coni sequently the confining of said batteryand transformer at the places with the stationary contacts or at theconnecting station whereby only few batteries and transformers will beneeded for a large number of stationary contacts, that offer thecontacting of said transmitter as well as the receiver and therethroughthe electric connection with the connecting station.

Furthermore, electro-magnets having cores, the pole ends thereof may bebranched.

What is claimed is:

1. A telephone transmitter and a receiver, the latter associated with anelectro-magnet, both. the transmitter and receiver, having a diaphragmof non-metallic material, the diaphragm consisting of a core held bystretching means in such position that it assumes the shape of a cone,and both cores of the diaphragms lacquered and at least the diaphragm ofthe receiver having iron filings embedded in the lacquer at the parts ofthe diaphragm only that are distant from said stretching means andfacing the poles of said electro-magnet.

2. A telephone transmitter having a non-metallic diaphragm, a partsecured to the latter and touching a metallic electrical conducting partof flexible property, and other metallic means of flexible propertytouching said metallic electrical conducting part, and both saidmetallic electrical conducting part and said other metallic meansadapted to vibrate in unison with said diaphragm, and said metallicmeans in connection with an electric circuit, transforming thevibrations into electrical impulses.

3. A telephone transmitter, a diaphragm of non-metallic material,comprised in said transmitter, the diaphragm lacquered and ironparticles embedded in said lacquer, a membrane of metal, a stiff andlight part secured to said diaphragm and having an end, the latternormally touching slightly the membrane of metal and impulses andimpress the latter upon other-electrical conductors inclu ng atransformer. i

4. A telephone transmitter, a diaphragm of non-metallic materialcomprised in said transmitter, the diaphragm lacquered, a membrane ofmetal, a light means secured to said diaphragm and touching lightly saidmembrane of metal and adapted to transfer the vibrations of saidnon-metallic diaphragm upon said membrane of metal, the latter connectedin an electric circuit, a vessel of insulating material, said membranecovering part of said vessel, the latter containing gaseous matter thatis adapted to take up the vibrations of said membrane of metal andimpress them upon other electrical conductors, including a plate and atransformer, in form of electrical impulses.

5. A telephone receiver and transmitter, adapted to be carried in beconnected and disconnected from contacts that are in connection with thestationary circuit connections of the connecting station, a dish-likepart permitting the placing upon it said receiver and transmitter, astandard adapted to hold said transmitter and a standard to hold saidreceiver in the vertical positions.

6. A telephone receiver and transmitter, a dishlike part adapted toreceive said receiver and transmitter for the handy handling thereof,said dish-like part having a part consisting of electrical contacts andthe latter included in an electrical circuit that includes also a meansfor announcing a call, one of said electrical contacts adapted todisconnect itself from the other when said receiver is taken from saiddish-like part, thus opening the circuit in for announcing is included,same in its function.

7. A telephone receiver and transmitter, stationary circuit connectionsof a telephone system, including electrical connecting parts at variouslocations and some including a cord with electrical conductors, thetransmitter having electrical connecting parts and adapted to beelectrically connected to said electrical connecting parts that includethe conductors in said cord, a push button adapted to stay in thepushed-in position and thus make an electrical connection that closesthe circuit in which said transmitter is included, and another pushbutton for pushing the rst mentioned push button out and in circuitdisconnecting position.

8. Stationary circuit connections and a connecting station of atelephone system including electrical connecting parts at variouspoints, a telephone receiver and transmitter having connecting means forthe electrical connection with said electrical connecting parts andadapted to be electrically connected to said electrical conparts everytime a telephone call is to and likewise to be detached from saidelectrical connecting parts every time the telephone call is finishedand adapted to be carried in a pocket or in a hand bag, the transmittercomprising circuit closing and opening switch means, said switch meansadapted to let the calland thus stop the er make electrical connectionlwith said connecting Vstation at anytime after circuit connections;

9.Y A telephone a predeterminedvalue is inserted. Y l

10. A telephone system comprising a connecting station with an in theelectro-magnet of that receiver, and said electric impulses may beamplified by an amplifier at said connecting station.

11. A telephone ing station and electric conductors leadingtheretro-magnets into sound, increasing and decreasing it in intensitycommensurate with the insys/tem comprising a connecting statlon andelectric conductors leading to vari-vV lring station and means creaseand decreaseA of the electric impuls-es set up in the conductors thatare in electrical connection with said electro-magnets, an amplifier atsaid connecting station, electrical conductors leading from everytransmitter to said connectfor connecting them to said amplifier,separate electrical conductors leading from said receivers to saidconnecting station and means for connecting them to said amplier, insuch way, as to receive the output of the amplified electric impulsesset up in the electrical conductors oi said transmitters, means forelectrically connecting the electrical conductors of one of saidreceivers and of one of said conductors that will be at hand at any ofsaid points and thus permit'the connection by means of known contacts oftwo telephones of parties that want tov have conversation togetherwithout said' electrical conductors being then in electrical connectionwith said amplifier and consequently. without amplification of the soundproduced by the transmitter.

12. A telephone system comprising a connecting station and electricconductors leading therefrom to various points including also telephonebooths, receivers and transm'tters at said points and electric contactsfor the insertion of contacts ofY detachable receivers andtransr'nitters',A the receivers' comprising electro-magnets anddiaphragms, the latter adapted to transform the' magnetic impulses, setYup in said electro-mag-r nets, into' sound, commensurate with theintensity of said magnetic impulses,` an amplier at said connectingstation and connecting meansfor simply electrically connecting two ofsaidY electrical conductors,r connecting means for connecting one ofsaid electrical conductors with said amplier and a relay the winding ofwhich is in electrical connection with the electrical conductors thatreceive the output of said amplifier, a contact of said relay and an'armature thereofV normally contacting with said contact, anotheramplifier, said contact electrically'connected-with. said otheramplifier another relay, the winding of the latter electricallyconnected with said other amplier and adapted to interrupt at times' oneof said electrical conductors and at the same time to establishelectrical connection with said other amplier and with the receiver andtransmitter in 'connection'Y with said last mentioned electricalconductor, so that the output of said other amplifier. reaches the lastmentioned receiver.

HEINRICH KARL.

